The most important step in newborn resuscitation is establishing effective ventilation because most newborns requiring resuscitation suffer from respiratory failure rather than cardiac arrest. Effective ventilation ensures adequate oxygen delivery and removal of carbon dioxide, crucial for reversing hypoxia and preventing brain injury. Without establishing a patent airway and proper ventilation, other interventions like glucose or antibiotics are ineffective. Providing warmth is important but does not replace the need for respiratory support. Thus, ventilation is the cornerstone of successful neonatal resuscitation.

Reference: Textbook of Neonatal Resuscitation, American Academy of Pediatrics, 7th Edition.